Theme Override of Webform E-Mail

I'm having a time of it trying to figure out how to override the background of a Webform generated e-mail. It appears to default to the body color of the theme I'm using and I just need good old WHITE. I need to set the color of mimemail-body in the outgoing e-mail. I've copied webform-mail.tpl.php over to my theme folder but nothing I've tried has worked. Should be a simple thing.